The adverse consequences of obesity are pleiotrophic for the mammalian organism. Animal models of obesity that allow careful characterization of the pervasive metabolic effects of the disease are vital to the success of our mission. To enhance research into the causes and consequences of obesity, we established a mouse phenotyping core. The primary goals of this core are to develop and provide standardized state-ofthe- art methods for the analysis of animal models of disease. The core applies the analytical expertise of ten laboratories to provide histology, neuroanatomy, gene expression, mass spectrometry, physiology, lipid, glucose, metabokine, and behavioral assays. The core is directed by Russell, Elmquist, and Scherer and is staffed by a dedicated team of skilled technicians who utilize existing equipment to perform optimized assays on samples provided by TORS investigators. Currently available assays include histological staining and antigen detection, in situ mRNA hybridization, real time reverse transcriptase-PCR, microarray analysis, laser capture microdissection, small molecule mass spectrometry and metabolite profiling, metabolic cage analyses, complete lipid balance studies, magnetic resonance and computed tomography imaging, glucose tolerance and clamp analyses, serum hormone measurements, routine blood chemistries, exhaustive behavioral analyses, and synaptic plasticity measurements in brain slices. As new research findings dictate, novel methodologies are developed and made available by the core. For each experiment, results are collected, calculated, and compiled in electronic format and returned to submitting investigators. The availability of the services provided by this core accelerates the pace of our research, allows centralized troubleshooting, and facilitates the efficient utilization of existing expertise and resources. The mouse phenotyping core is a crucial component of our Roadmap effort that brings together a diverse team of scientists and clinicians to ensure that discoveries made in obesity research are rapidly translated into advances in patient care.